Whereas students in most parts of the United States are typically asked simply to recognize a single fact they have memorized from a list of answers, students in high-achieving countries are asked to apply their knowledge in the ways that writers, mathematicians, historians and scientists do.
In the United States, a typical item on the 12th grade National Assessment of Educational Progress, for example, asks students which two elements from a multiple choice list are found in the Earth's atmosphere. An item from the Victoria, Australia, high school biology test (which resembles those in Hong Kong and Singapore) describes how a particular virus works, asks students to design a drug to kill the virus and explain how the drug operates (complete with diagrams), and then to design and describe an experiment to test the drug - asking students to think and act like scientists.
This kind of testing would clearly pay for itself just from the patent rights to the anti-viral drugs designed by the high school test-takers. They must be worth billions!